When Should I Offer My Tree a Drink?

With spring at our doorstep, planting new trees and shrubs seems to be on everyone’s mind. One of the most common questions we arborists get when planting trees is, “What do I do about water?”

Trees can be a large investment, and no one wants to see them die in the first few months or year because of improper watering. That said, many people seem to be lost in the woods when it comes to quantity and frequency of waterings, but with a few simple rules to remember, your newly planted trees can be set up for success.

For a new tree of roughly 2 inches diameter (measured about a foot off the ground) and average height planted in the spring or summer, you’ll want to give it water almost daily for the first month, and then every 2 or 3 days for the next three months. After that, weekly waterings are needed until the tree is established.

In Richmond’s USDA hardiness zone, getting fully established may take anywhere from 6-8 months for a 1-inch diameter tree — all the way to nearly 2.5-3 years for a 4-inch diameter tree.

Given that, the single most important thing to remember is that every tree, every yard, and every year is different– so there are no hard and fast rules. These are just meant to be guidelines to get you started.

You should never add water to already saturated soil. Oxygen is just as important to trees as water, so the drying out of the soil in between waterings is of vital importance. This filling of the soil pores with water, then air, then water again is what trees need. Adding too much water too frequently can keep the soil saturated and doesn’t allow the air to penetrate to the roots the way they need. Natural precipitation may keep the soil saturated for days (or weeks!) after a watering, which brings me to our last point.

The best recommendation I always give to new tree owners is by far the most fun: get your hands dirty! Walk out to your new tree. Get to know it. Dig down 5 or 6 inches into the soil of the root ball. Does it feel dry? Water! Can you pick up some soil, squeeze it, and it forms a squashy wet ball? Give it another day! Then test again. This frequent testing with your hands will help give you a baseline for how your own yard and the root ball of the new tree holds moisture. After a few weeks or a month, you’ll find you don’t need to get your hands dirty anymore, and you will instinctively know when your tree needs some water, and when to hold off.